My Ford F150 won't shift out of low range. What is wrong with it?

 

Sometimes after I put mine in a hard pull, I had to "rock" the pressure off of my t-case(np203) by backing, then pulling forwards a little, then I could get it out of lo range. Also, there is a great forum here on trans, differ, and transfer cases you might want to go to, just go up to the top of this page and hit "forums" and scroll way down, good luck

 

If it is push button transfer case it could be the seloid on the t case it's self. I'm went out about three years ago biut was easy to get too and change. Good luck.